FIELD OF THE INVENTION
The present invention relates generally to an apparatus for determining the distance between a vehicle and a fixed object, and more particularly to a system and method for assisting a driver who is backing a tractor/trailer up to a loading dock by visually and continuously letting the driver know how close the rear of the trailer is to the loading dock, thereby providing information to the driver to prevent the trailer from being backed into the loading dock and incurring the commensurate damage associated with such a collision.
Much of the cargo moved from one location to another is moved by heavy trucks, with the most common of such trucks being a tractor/trailer combination in which a large tractor is used to tow a variety of long trailers from place to place. It will be appreciated by those skilled in the art that such trailers extend well back of the cab of the tractor pulling them. While truck drivers are generally skilled in the operation of such large tractor/trailer combinations, one of the more difficult operations which they must perform on a frequent basis is backing the trailer up to a loading dock.
The driver must ensure that the tractor/trailer is being backed up in the proper lane, which may frequently be located between two other tractor/trailers, with relatively little space therebetween. In addition, the driver must accurately gauge the distance between the rear of the trailer and the edge of the loading dock, so that the tractor/trailer can be stopped in the proper position just prior to running into the loading dock. While it is relatively easy to stop the tractor/trailer in the proper position when assisted by a second person located adjacent the loading dock and at one side of the trailer, it will be appreciated that it is difficult for the driver alone to back the trailer to a position just short of the loading dock.
When the driver of a tractor/trailer does not have assistance from a second person, in order to avoid backing the trailer into the loading dock it may be necessary for the driver to stop at a position which may be well short of the loading dock, get out of the tractor, go to the rear of the trailer to see how much distance remains between the rear of the trailer and the loading dock, and then return to the cab of the tractor and continue backing up. More than one such trip from the cab of the tractor to the rear of the trailer may be necessary to properly position the rear of the trailer at the loading dock without hitting the loading dock. With the heavy weight of the tractor/trailer, particularly when the trailer is loaded, it will be appreciated that significant damage can be done to the rear of the trailer even at very slow speeds.
It is accordingly the primary objective of the present invention that it provide the driver of a tractor/trailer with an apparatus and a related method of operating the apparatus for providing an indication of the distance remaining between the rear of the trailer and a loading dock or other similar fixed object as the trailer is backed toward the loading dock or other fixed object. It is a further objective of the collision avoidance system of the present invention that it be permanently mountable on a loading dock or other fixed object in a manner such that it will reliably determine the distance between the rear of a trailer being backed toward the loading dock or other fixed object and the loading dock or other fixed object. It is a related objective of the collision avoidance system of the present invention that it be capable of providing a minimum offset distance between the rear of a trailer and the loading dock or other object such that there may be an adjustable small space, e.g. a few inches, between the rear of the trailer and the loading dock or other object when the tractor/trailer is properly parked at the loading dock.
It is also an objective of the collision avoidance system of the present invention that it be operable in a manner not requiring the driver of the tractor/trailer to get out of the cab of the tractor in order to determine the distance between the rear of the trailer and the loading dock or other fixed object. It is a related objective of the collision avoidance system of the present invention that a display be installed on the loading dock or other fixed object in a position which may easily be viewed by the driver while the driver is located in the cab of the tractor. It is a further related objective of the collision avoidance system of the present invention that the display mounted on the loading dock or other fixed object may be viewed by the driver either by looking out the window of the cab of the tractor and back toward the loading dock or other fixed object, or by looking in the side view mirror of the tractor back toward the loading dock or other fixed object.
The collision avoidance system of the present invention must be of a construction which is both durable and long lasting, and it should also require little or no maintenance to be provided by the user throughout its operating lifetime. In order to enhance the market appeal of the collision avoidance system of the present invention, it should also be of relatively inexpensive construction to thereby afford it the broadest possible market. Finally, it is also an objective that all of the aforesaid advantages and objectives of the collision avoidance system of the present invention be achieved without incurring any substantial relative disadvantage.